Generally, a high voltage cable is a kind of cable which is being used in a process of power transmission of electric power supply having a high voltage, and it is impossible to construct a whole power transmission line as a single line because a high voltage cable has a limited length. Accordingly, a power transmission line is constructed by connecting a plurality of high voltage cables using joint boxes.
A joint box of high voltage cables described above should be equipped with various components including a conductive sleeve for mutually fixing and conducting conductors, each of which forms an end part of the high voltage cables, and an electrode unit, being fixed by the conductor sleeve, for maintaining electrical insulation performance consistently.
FIG. 1 illustrates a front cross-sectional view of a joint box according to prior art, and FIG. 2 illustrates a combined cross-sectional view of the components of a joint box according to prior art.
Referring to FIGS. 1 and 2, a joint box 100 according to prior art, for example, compress a sleeve 120 for connecting conductors 115 of high voltage cables 110; an elect rode unit 130 being connected to the sleeve 120 through an electrode component 135; a tube body 140 for wrapping insulator 145 which is filled around the electrode unit 130; and stress relief covers 150, being coupled to both ends of the tube body 140, for pressing tightly the insulator 145 to the high voltage cables 110.
In the prior art joint box 100, as illustrated in FIG. 2, the conductors 115 are mutually connected by the sleeve 120 by inserting the conductors 115 into both sides of the sleeve 120 and then pressing them, under a condition that the sleeve 120 is exposed to a left or right side from the electrode unit 130. After that, a connecting procedure between the high voltage cables 110 and the electrode unit 130 is completed by placing the sleeve 120 at a center portion of the electrode unit 130 and then fixing the sleeve 120 to the electrode component 135 of the electrode unit 130 either using a fixing screw 137 or using a force-inserting manner.
However, in the prior art joint box 100 as described above, there is a problem that either one of metal sheaths 117 of the high voltage cables 110 is required to be cut by a length corresponding to that of the electrode unit 130, because the mutual connection between the conductors 115 and the sleeve 120 should be made under a condition that the sleeve 120 is exposed to a left or right side from the electrode unit 130.
Accordingly, an additional process of cutting either one of the metal sheaths 117 by a length corresponding to that of the electrode unit 130 is required in prior art and thus the length of the joint box 100 is extended so that the manufacturing costs are increased, and there is a space limitation as well that jointing work of a joint box is not available at a confined place due to the increased length of the joint box 110.